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VIII. Urban climate classificalion,
Local Climate Zones
URBAN CLIMATOLOGY
8.1 Urban Climate Classification
Chandler (1965) , Climatic Regions of London
Topoclimatic regions of Brno
(Quitt 1977)
Synthetic map of temperature,
moisture and wind conditions in Brno.
8.1 Urban Climate Classification
Urban climate classification
using
Cluster analysis
Iteration algorithm - from initial position of typical LCZ „training
sites“ it searches repeatedly for the most similar parts (cells) of
multidimensional feature space
Feature space - axes defined with typical characteristics used for
separation of LCZ
Database (feature space) Brno
Albedo
Roughness
Buildings density
Density of dwellers
Elevation model
NDVI
Slope orientation
Relative number of residential
houses
Land use category
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Classifications of Brno Climate
(Stráník 2014)
Clusters are usually aggregated to individual classes
Urban Climate
zones (Oke 2004)
8.2 Concept of the Local Climate Zones (LCZ)
• Until recently, there was no universal approach to describe and
characterize the physical nature of cities for urban climatologists.
• Much of the existing terminology was not transferable across
cultural and geographical regions.
• To help standardize methods of observation and documentation in
urban heat island studies, Stewart and Oke (2012) developed the
Local Climate Zone (LCZ) classification scheme.
Local Climate Zones classification system
Local Climate Zones, Oke and Stewart (2009)
Local Climate Zones classification system
• Local climate zones are formally defined as regions of uniform
surface cover, structure, material, and human activity that span
hundreds of meters to several kilometers in horizontal scale.
• Each LCZ exhibits a characteristic geometry and land cover that
results in characteristic screenheight temperature regime that
is most apparent over dry surfaces, on calm, clear nights, and in
areas of simple relief.
• LCZ scheme consists of 17 standard LCZs, of which 15 are
defined by surface structure and cover and 2 by construction
materials and anthropogenic heat emissions. The standard set is
divided into “built types”(1–10), and “land cover types”(A–G )
Local Climate Zones classification system
There are several methods how to define LCZ:
• Method based on automatic classification of satellite imagery
(WUDAPT, Bechtel et al.)
• GIS method using geo-database and a set of logical rules in the
form of decision tree
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LCZs classification algorithms
• WUDAPT (World Urban Database and Access Portal Tool) – automatic
classification of multi-source satellite images
LCZs classification algorithms
• GIS and map algebra, decision trees
Brno - LCZs
LCZs of Brno (left) and Land Surface Temperature fields derived from LANDSAT 8 and TERRAASTER
thermal images
LCZs of Brno
Statistical description of land surface temperatures (LST) in individual LCZs in Brno area for
two different dates (left). Blue points in right indicate no statistical difference in LST of
corresponding zones
8.3 Final remarks and questions
1. Why is simple Urban – rural division insufficient in urban
climatology?
2. What were the main reasons to create LCZ classification
scheme in urban climatology?
3. How can be LCZs used for mitigation negative effects of
UHI and heat waves?
4. How can be LCZ useful e.g. to architects, planners,
ecologists, and engineers?